The present invention relates to electric generator unit housings for refrigerated freight containers which are transportable by truck, rail, and ship. More particularly, the invention relates to an electric generator unit housing which may be mounted in both a "clip-on" fashion, i.e. mounted to the front wall of a refrigerated freight container, or in an "underslung" fashion i.e. mounted to a container chassis. For purposes herein, it should be understood that the term "housing" is defined herein to include the mechanisms which are used to attach the electric generator unit housing to the refrigerated freight container or container chassis.
Refrigerated freight containers which are transportable by truck, rail, and ship, are well known in the art. Electric generator units which attach either to a chassis transporting such a container, or which attach directly to the refrigerated freight containers to provide the necessary power are also known in the art. Indeed, standards for such refrigerated freight containers and their attachments have been promulgated by ANSI and ISO and specify loads and fittings to be used with containers utilized in international commerce.
Those skilled in the art will recognize that different requirements present themselves for each mode of transportation of the containers. For example, in the railroad mode, a higher fore and aft load requirement is necessary than on ship due to coupling forces which occur during reclassification of railcars. In the ship mode, to permit stacking and/or proper loading it is preferable that the generator unit housings not extend above the top plane of the refrigerated container. In the truck mode, if the generator housing is mounted to the front of the container ("clip-on"), it is necessary to provide swing clearance for the tractor pulling the chassis mounted container. If the generator housing is mounted to the chassis ("underslung"), a sufficient ground clearance is necessary to prevent damage from road hazards.
Presently in the art, there are no generator unit housings which meet all the requirements for truck, rail, and ship transport. For example, generator units which are attached in an underslung fashion to container chassis are known but are only useful in the truck mode. This is so because they are located beneath the chassis and cannot be used when a container is stacked onto another container or when the container is placed on a railcar. Likewise, the housing of one clip-on unit known in the art which attaches to the front top area of the container, extends past the top plane of the container and thereby inhibits the transfer of the container between ship and land. Such difficulties obtain due to the fact that the crane spreader used in the transfer is impeded by any projection above the top plane of the container. Still another housing which attaches to the front top area of the container through the use of special fittings to make it transferrable by crane extends into the swing clearance radius required by the tractor and thus does not meet that requirement.
The fact that the generator unit housings of the art are unable to meet all the requirements of rail, truck, and ship transportation is not the only problem in the art. An additional problem is that some refrigerated containers are particularly arranged to be equipped with underslung generators, while other containers are particularly arranged to be equipped with clip-on generators. This lack of uniformity forces the operators to maintain two imcompatable sets of generators which leads to unacceptable expenses and complications. Moreover, none of the generator units of the art are capable of being attached to the refrigerated containers in both the clip-on and underslung arrangements.